A New Tree Construction Algorithm For Scalable Multicast In Mpls Networks

Multicast delivers data to multiple receivers efficiently in a network. However the number of forwarding states maintained in the network layer increases linearly with the number of existing multicast channels, which is a critical scalability issue that delays the deployment of IP multicast in the Internet. MPLS coexists with many existing network protocols and can provide scalability for how these protocols are used in today's networks. In a MPLS network, forwarding states are removed from non-branching routers on multicast trees and packets are label switched by LSPs in non-branching routers. In this paper, we propose a new multicast tree construction algorithm to further reduce the number of forwarding states stored in branching routers through merging multicast subtrees. Simulation results show that our new algorithm can achieve 34% reduction in the number of multicast forwarding states.